Hoisting indicator



n01 STING INDICATOR Filed June 8, 1945 INVENTOR.

WLW

-. ATTORNEY Patented Jan. 14, 1947 STATES (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 1 Claim.

This invention relates to indicators and more particularly to apparatus for ascertaining the correct alignment of hoisting devices, especially when said hoisting devices are making sensitive lifts of heavy objects.

In the lifting of large and heavy objects out of their jackets such as, for example, the lifting of turbine rotors from their casings, it is necessary to accurately center the crane before a lifting force is applied to said heavy objects. It is apparent that should a lifting force be applied to the crane without the axis of said crane passing through the axis of the turbine rotor or other object lifted by the crane, a side thrust by the rotor upon its casing will result, said thrust being of sufficient force to damage either the turbine rotor or the casing, perhaps both. I

Previous to this invention, the lifting of an object from its casing was done by trial and error, the load being lifted slightly several times until a balanced load at the end of the hook of the crane was sensed by the crane operator. the crane operator felt satisfied that the load he was lifting was balanced, he applied the necessary lifting force to hoist the load out of its jacket.

It is an object of this invention to provide means to increase the accuracy in aligning lifting cranes.

A further object is to make said means for aligning lifting cranes visible from any position by an observer.

Further objects and advantages of this invention, as well as its construction, arrangement and operation, will be apparent from the following description and claim in connection with the accompanying drawing, in which the single figure is a front view of a lifting assembly showing an embodiment of this invention.

Referring to the figure there is shown a crane I consisting of a hook, block and cable. The hook portion consists of a pair of hook arms II, a safety clamp I2 which rests on the tips I3 of said arms II to safeguard against slippage of a line from said arms II, said clamp I2 riding on the shaft I4 of the hook.

The shaft I4 is contiguous with an enlarged portion or head I5, said head I5 being secured by bolts I6 and nuts H to a framework I8. A block I9 is similarly secured to the top portion of the framework I4, cables 20 girdling said block IS, the cables 28' being attached to lifting means (not shown).

Near the foot of said framework I8 is a rectangular band 2I which serves to reenforce the framework I8. This band 2| has indicating bars 25 are free to move in an are without inter- When ference from nuts 21.

The plumb bars 24 and 25 are secured to their respective supports by means of a ball and socket or equivalent universal suspension joint 28 to prevent binding of said plumb bars '24 and 25 against their supports.

In operation, the arms II of the cranes hook are secured to an object that is to be lifted out of a surrounding jacket. Sufficient tension is applied to the cables 20 in order to barely lift the object from its surrounding jacket. If the crane block should be tilted when said body is thus hoisted, the block bars 24 and 25 will swing out of registration with their respective center line marks 22. Since the plumb bars 24 and 25 are I suspended from supports that are at right angles to each other, any tilting about a horizontal plane will be registered. The cables 28 are then adjusted, adjustment being made according to the amount Of swing of said plumb bars 24 and 25 away from registration with their respective center lines 22. These initial hoists can be quickly determined by an observer at the ground so that the time involved in determining the proper cable adjustment for a balanced load prior to applying the final hoisting force that will lift a body from its surrounding jacket will be considerably diminished.

This invention removes the guesswork in hoisting operations. Moreover, by aiding in the accurate balancing of a load prior to lifting said load, it can prevent damage to sensitive portions on the surface of very valuable heavy equipment.

To further prevent undue swing of the pendulums 24 and 25, guard blocks (not shown) can be secured to the framework I8 to the right and left of said pendulums 24 and 25. These guard blocks will prevent undue swing of the pendulums 24 and 25, thus hastening the lining up of the said pendulums with their respective center lines.

It is to be understood that various modifications and changes may be made in this invention without departing from the spirit and scope thereof as set forth in the appended claim.

The invention described herein may be manufactured and used by or for the Government-of 3 the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed:

In a hoisting apparatus, a vertically disposed framework, hook means secured to the foot of said framework, adjustable hoisting means 56- cured to the top of said framework, reenforcing bands girdling said framework, indicating markings on the lower reenforcing band, freely rotatable plumb bars universally connected to and depending from said framework, said bars swinging relative to said indicating markings to register the verticality of said framework.

JOHN CHARWINSKY. 

